.head
  width: 100%;
  height: 2rem;
.header
  width: 100%;
  height: 2rem;
  position: fixed;
  left: 0;
  top: 0;
  background-color: #fff;
  border-bottom: 2px solid #ff8000;
.header h4
  width: 100%;
  text-align: center;
  line-height: 2rem;
  font-size: 1.4rem;
